Some more word on the add-in.

I'm still struggling with duplicate event handlers being called, functions exiting early because of this.
For now, it appears that the workbook is not loaded because of this, so most things are broken for now.

.eslintrc.json

 {
   "plugins": [
-    "office-addins"
+    "office-addins",
+    "prettier"
   ],
   "extends": [
-    "plugin:office-addins/recommended"
-  ]
+    "plugin:office-addins/recommended",
+    "plugin:prettier/recommended",
+    "esling:recommended"
+  ],
+  "env": {
+    "browser": true,
+    "node": true,
+    "es2021": true
+  },
+  "globals": {
+    "Office": "readonly",  // Declare Office as a global variable
+    "XLSX": "readonly"
+  },
+  "rules": {
+    "no-multiple-empty-lines": "off", // Example: turn off the multiple empty lines rule
+    "prettier/prettier": "error" // Enforce Prettier formatting as ESLint errors
+  }
 }

.prettierrc

+{
+  "printWidth": 80,
+  "tabWidth": 2,
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "all",
+  "endOfLine": "auto"
+}
\ No newline at end of file

package-lock.json

@@ -20,7 +20,7 @@
         "acorn": "^8.11.3",
         "babel-loader": "^9.1.3",
         "copy-webpack-plugin": "^12.0.2",
-        "eslint-plugin-office-addins": "^3.0.2",
+        "eslint-plugin-office-addins": "^3.0.3",
         "file-loader": "^6.2.0",
         "html-loader": "^5.0.0",
         "html-webpack-plugin": "^5.6.0",

package.json

@@ -37,7 +37,7 @@
     "acorn": "^8.11.3",
     "babel-loader": "^9.1.3",
     "copy-webpack-plugin": "^12.0.2",
-    "eslint-plugin-office-addins": "^3.0.2",
+    "eslint-plugin-office-addins": "^3.0.3",
     "file-loader": "^6.2.0",
     "html-loader": "^5.0.0",
     "html-webpack-plugin": "^5.6.0",
@@ -59,4 +59,4 @@
     "last 2 versions",
     "ie 11"
   ]
-}
+}
\ No newline at end of file

src/taskpane/taskpane.html

@@ -15,12 +15,19 @@
     <p id="messageText"></p>
   </div>
 
-  <fieldset>
+  <!--fieldset>
     <legend>1. Select data source (Excel file):</legend>
     <input type="file" id="excelFileInput" accept=".xlsx, .xlsm, .xlsb, .xlts, .xltm, .xls" />
     <div class="worksheet_select">Worksheet: <select id="worksheetSelect" disabled></select></div>
+  </fieldset-->
+  <fieldset>
+    <legend>1. Select data source (Excel file):</legend>
+    <button id="selectFileButton">Select File</button>
+    <span id="selectedFileName" style="margin-left: 10px; font-slant: italic;">No file selected</span>
+    <div class="worksheet_select">
+      Worksheet: <select id="worksheetSelect" disabled></select>
+    </div>
   </fieldset>
-
  
   <fieldset>
     <legend>2. E-Mail - Placeholder fields:</legend>
@@ -50,9 +57,12 @@
     </div>
   </fieldset>
 
+  <button id="sendNowButton" disabled>Send now</button>
+  <button id="sendLaterButton" disabled>Send later</button>
+
 
   <div id="dataPreview"></div>
-  <script src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.18.5/xlsx.full.min.js"></script>
+  <script src="https://cdn.sheetjs.com/xlsx-latest/package/dist/xlsx.full.min.js"></script>
   <script src="https://appsforoffice.microsoft.com/lib/1/hosted/office.js"></script>
   <script src="taskpane.js"></script>
 </div>